Using my senses.

I wear rubber gloves.  The knife is more than just a cutting tool. I feel how the knife vibrates as it passes through the flesh of the fish. Scraping gently along a bone or a slight resistance as it travels round sinew. It tells me where it is. I feel which part of the blade is 'talking' to me. The importance of the shape of the blade and it's sharpness is everything. I remove the fins and skin from the back of the fish as these are of a tougher texture to the flesh and block and confuse the vibrations I need to feel. The rubber gloves insulate my senses from unnecessary distraction. Wet, cold, very cold !  Allowing my senses to focus on the blade and the flesh.